Weld joint cleaning method

Abstract

The invention relates to the technical field of weld joint cleaning, in particular to a weld joint cleaning method which comprises the steps that whether a switch mode power supply is switched from a constant power control mode to a control mode for weld joint cleaning equipment or not is determined; determining the delay duration of switching from the constant power control mode or the constant current control mode to the constant voltage control mode; the weld joint areas acted by all the control modes are marked as corresponding cleaning areas; whether the rotating speed of the electric brush in the corresponding cleaning area is adjusted or not is determined, or the contact area of the position where the electric brush is located at the jumping moment is adjusted, and the propelling rate of electrolyte is determined; actual cleaning is conducted on the to-be-cleaned weld joint; and detecting the flatness of the surface of the welding seam until the flatness of the surface of the welding seam meets the requirement. The welding seam cleaning efficiency is improved, and the stability of the cleaning process is improved.

Description

Technical Field

[0001] The invention relates to the technical field of weld cleaning, and in particular to a weld cleaning method. Background Art

[0002] In the prior art, welds are cleaned by equipment that cleans, polishes, marks and passivates welds. All functions are achieved through the use of electric current, brushes, brushes, surface cleaners and other forms and chemicals. Chemicals are applied to the material using a cleaner or through a conveyor belt and reacted through the electric current to achieve the purpose of cleaning impurities on the weld.

[0003] Chinese patent publication number: CN105750714A discloses a steel plate submerged arc welding process, including the following steps:

[0004] 1) Preparation before welding

[0005] 1.1) Prepare welding wire flux. Remove dirt, oil, rust and other substances from the welding wire and coil it regularly in the welding wire reel. The flux should be dried in advance (bake at 250℃ for 1-2 hours) and no other impurities should be mixed in. The welding joint of the workpiece should be degreased, decontaminated and dehydrated.

[0006] 1.2) Turn on the three-phase power switch of the control box;

[0007] 1.3) Check the welding equipment. Under no-load conditions, check whether the positioner rotates forward and backward, and whether the welding wire moves upward and downward normally. Rotate the welding speed regulator to observe whether the rotation speed of the positioner is normal. Loosen the welding wire feeding wheel, try to control the start button and stop button to see whether the action is correct, and rotate the arc voltage regulator to observe whether the speed of the wire feeding wheel is correct.

[0008] 1.4) Clean the conductive tip and adjust the pressure of the conductive tip on the welding wire to ensure good conductivity and unobstructed wire feeding;

[0009] 1.5) Preliminarily determine the welding specifications according to the thickness of the weldment. Before welding, weld a test piece of the same thickness. Adjust the welding specifications according to the penetration of the test piece (X-ray or cut weld, depending on the fusion of the weld section) and surface formation. Determine the best welding specifications after repeated tests.

[0010] 1.6) Align the nozzle with the weld, and fine-tune the lateral adjustment hand wheel of the welding machine to align the welding wire with the weld;

[0011] 1.7) Press the wire down button to bring the welding wire close to the workpiece. The distance between the welding gun head and the workpiece should not be less than 15mm, and the extension length of the welding wire should not be less than 30mm.

[0012] 1.8) Check whether the position of the positioner rotary switch and circuit breaker is correct, and adjust the rotation speed;

[0013] 1.9) Open the flux drain gate to allow the flux to cover the welding wire. The height of the flux layer is generally 30-50mm;

[0014] 2) Welding work

[0015] 2.1) Press the start button, the welding wire will be pulled up, and then it will automatically go down to contact and rub with the workpiece and cause an arc, so as to ensure the normal burning of the arc and the normal welding work;

[0016] 2.2) During the welding process, the ammeter and voltmeter must be observed at any time, and the relevant regulators (or buttons) must be adjusted in time to meet the required welding specifications. When the network voltage is found to be too low, the welding work should be suspended immediately to avoid seriously affecting the quality of penetration. Work can be resumed after the network voltage returns to normal. When using 4mm welding wire, the weld width is required to be >10mm, the welding speed is ≈15m / h when welding the groove, the voltage is ≈24V, the current is ≈300A, and when approaching the surface, the voltage is >27V and the current is ≈450A; when welding ball valves, generally try to use low voltage and low current when welding the first layer, because there is no good cooling and the temperature rise is too high to damage the internal parts and the internal stress is large; when welding the second layer and thereafter, water cooling must be passed, and the voltage and current can be increased, so that the welding slag is easy to clean;

[0017] 2.3) During the welding process, attention should also be paid to whether the penetration and surface forming of the weld are good. The penetration can be judged by observing the red heat of the arc burning on the back of the workpiece. The surface forming can be observed by removing the welding slag after welding a short section. If the penetration and surface forming are found to be poor, timely adjustment should be made to save them to reduce losses;

[0018] 2.4) Pay attention to whether the welding wire is aligned with the center of the weld to prevent welding deviation. The welder's observation position should be the same as the position when adjusting the welding wire during arc initiation to reduce line of sight errors. For example, when welding the inner weld of a small diameter cylinder, the direction of the arc can be judged based on the red heat on the back of the weld to determine whether it is skewed and make adjustments;

[0019] 2.5) Always pay attention to the amount of flux in the flux funnel and add it at any time. When the flux does not flow smoothly, use a rod to clear the channel in time to remove large obstacles.

[0020] It can be seen that the steel plate submerged arc welding process has problems such as insufficient driving voltage during the electrolytic cleaning process, which leads to insufficient current flowing when high resistance is generated, thereby reducing the cleaning stability, excessive current when dynamically reducing resistance, causing the electrolyte to be burned, and uneven distribution of contact resistance when the brush cleans the weld, resulting in reduced cleaning efficiency. Summary of the invention

[0021] To this end, the present invention provides a weld cleaning method to overcome the problems in the prior art such as insufficient driving voltage during the electrolytic cleaning process resulting in insufficient current flowing when high resistance is generated, excessive current causing the electrolyte to be burned when the resistance is dynamically reduced, and uneven distribution of contact resistance when the brush is used to clean the weld resulting in reduced cleaning efficiency.

[0022] To achieve the above object, the present invention provides a weld cleaning method, comprising:

[0023] Step S1, immersing the brushes on the weld cleaning device into the electrolyte in sequence and placing them on the weld to be cleaned;

[0024] Step S2, determining whether the switch mode power supply is switched from a constant power control mode to a control mode for a weld cleaning device according to the contact resistance of the brush, wherein the control mode further includes a constant current control mode and a constant voltage control mode;

[0025] Step S3, determining the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode according to the thickness of impurities on the weld to be cleaned, and pre-cleaning the weld to be cleaned;

[0026] Step S4, marking the weld areas affected by each control mode in the pre-cleaning process as corresponding cleaning areas;

[0027] Step S5, determining whether to adjust the brush speed of the brush in the corresponding cleaning area based on the fluctuation amplitude of the output voltage or output current of the weld cleaning equipment in the corresponding cleaning area,

[0028] Or, adjusting the contact area of ​​the brush at the moment of the jump according to the resistance when the control mode is triggered, and determining the propulsion rate of the electrolyte according to the temperature change in the contact area after the adjustment;

[0029] Step S6, starting the brush of the weld cleaning device to actually clean the weld to be cleaned according to the brush rotation speed / according to the contact area and the electrolyte flow rate;

[0030] Step S7, detecting the flatness of the weld surface to determine whether to repeat steps S5 to S7 until the flatness of the weld surface meets the requirements.

[0031] Furthermore, the start condition of the constant power control mode is that the contact resistance is within a preset resistance threshold.

[0032] The output power of the switch mode power supply in the weld cleaning device is proportional to the contact resistance, and the contact resistance is the ratio of the output voltage to the output current.

[0033] Furthermore, a start condition of the constant voltage control mode is that the output voltage of the switch mode power supply is greater than or equal to a preset voltage, and the output current is less than a preset current.

[0034] Furthermore, a start condition of the constant current control mode is that the output current of the switch mode power supply is greater than or equal to the preset current, and the output voltage is less than the preset voltage.

[0035] Furthermore, the process of step S3 includes:

[0036] Collecting the maximum impurity thickness on the weld to be cleaned;

[0037] When the maximum impurity thickness exceeds the preset thickness, it is determined that the wetting degree of the electrolyte does not meet the requirements, and the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode is increased.

[0038] The delay time is positively correlated with the maximum impurity thickness.

[0039] Furthermore, the process of step S5 includes:

[0040] Respectively obtaining a cleaning area of ​​the weld to be cleaned when the switch mode power supply is in the constant power control mode, the constant current control mode, and the constant voltage control mode;

[0041] In the region of the constant power control mode, the brush speed remains unchanged;

[0042] In the region of the constant current control mode, if the fluctuation amplitude of the output voltage is greater than the second preset voltage fluctuation amplitude, it is determined that impurities in the electrolyte are dense, and the brush speed is reduced;

[0043] In the region of the constant voltage control mode, if the fluctuation amplitude of the output current is greater than the second preset current fluctuation amplitude, it is determined that the electrolytic reaction degree of the weld surface to be cleaned does not meet the requirements, and the brush speed is increased.

[0044] The fluctuation amplitude of the output voltage is the absolute value of the difference between the maximum value and the minimum value of the output voltage in the region of the constant current control mode; the fluctuation amplitude of the output current is the absolute value of the difference between the maximum value and the minimum value of the output current in the region of the constant voltage control mode;

[0045] The brush speed in the constant current control mode is inversely proportional to the fluctuation amplitude of the output voltage; the brush speed in the constant voltage control mode is directly proportional to the fluctuation amplitude of the output current.

[0046] Furthermore, the process of step S5 includes:

[0047] If the fluctuation amplitude of the output voltage is greater than or equal to the preset first voltage fluctuation amplitude and less than or equal to the preset second voltage fluctuation amplitude, or the fluctuation amplitude of the output current is greater than or equal to the preset first current fluctuation amplitude and less than or equal to the preset second current fluctuation amplitude, it is preliminarily determined that the impurity treatment uniformity does not meet the requirements, and the jump moment resistance when the adaptive control mode is triggered is obtained;

[0048] If the jump moment resistance is greater than or equal to the preset jump moment resistance, it is determined that the impurity treatment uniformity does not meet the requirements, and the contact area is increased.

[0049] The increase of the contact area is proportional to the resistance at the transition moment.

[0050] Furthermore, the process of step S5 includes:

[0051] Obtaining a temperature change per unit time within the increased contact area of ​​the brush;

[0052] The advancement rate of the electrolyte increases with the increase of the temperature change.

[0053] The temperature change is the difference between the temperature at the end of the unit time and the temperature at the start of the unit time.

[0054] Further, in the step S7, if the flatness is greater than or equal to a preset flatness, it is determined that the weld cleaning is not completed;

[0055] If the flatness is less than the preset flatness, it is determined that the weld cleaning is completed;

[0056] The flatness is the average impurity thickness at each position on the weld to be cleaned.

[0057] Furthermore, the operating frequency of the switch mode power supply is not less than 100 kHz, and the peak-to-peak value of the output ripple of the output voltage is not higher than 2000 mV.

[0058] Compared with the prior art, the beneficial effect of the present invention lies in that the method of the present invention effectively reduces the ripple of the output voltage by using a high-frequency switching mode power supply, thereby improving the stability of the electrolyte, and by adjusting the adaptive control mode, the output voltage and the output current are adjusted separately, and the electrolyte is overheated and burned due to excessive output current when the resistance is reduced due to the dynamic change of the contact resistance during the electrolysis process, or the output voltage is insufficient to electrolyze impurities due to the increase of resistance, thereby causing incomplete electrolysis, and the power is kept constant by adjusting the control mode to increase the electrolysis stability, and the current density in the brush is kept constant by keeping the output current constant, thereby increasing the uniformity of the electrolysis of impurities, and the output voltage is kept constant by establishing a current up to the maximum current according to the basic resistance, thereby achieving an improvement in the electrolysis efficiency; During the electrolysis process when the brush contacts impurities, the intense electrolysis causes the electrolysis reaction temperature to increase, and the wetting degree on the brush decreases too quickly. The lower the wetting degree of the brush, the greater the resistance in the output circuit of the electrolysis device, which in turn increases the current, causing errors in the contact resistance of the switching adaptation control mode, and further causing damage to the weldment due to excessive current. By adjusting the delay time, the electrolysis accuracy is increased; by adjusting the brush speed and contact area of ​​the brush according to the electrolysis performance of different control modes, the cleaning effect is reduced in places with uneven contact resistance due to the constant current density of the brush under constant current control, or the impurities in the constant voltage control area require a large current, resulting in intense electrochemical reactions and impurities accumulation in the electrolyte. By adjusting the brush speed and contact area, the cleaning efficiency is improved and the cleaning stability and uniformity are improved.

[0059] Furthermore, the method of the present invention sets a preset resistance threshold, a preset voltage and a preset current so that the adaptive control mode of the switch mode power supply changes with the reaction conditions required during the electrolysis process, thereby ensuring that the contact resistance changes between the brush and the weld can be responded to and adapted in a timely manner during different electrolysis stages. When the contact resistance is low, the method automatically switches to a constant power control mode to prevent the electrolyte from overheating due to excessive current. As the electrolysis process proceeds or the impurity composition or contact resistance changes, the contact resistance gradually increases, and the method switches to a constant current control mode to keep the brush current density constant, thereby improving the stability of the electrolysis. When the required current is too large, the method switches to a constant voltage control mode to fully electrolyze the impurities, thereby improving the electrolysis effect.

[0060] Furthermore, the method of the present invention adjusts the brush speed according to different areas. Due to the uneven distribution of contact resistance in different areas, the same brush speed cannot better achieve the cleaning of the weld. The electrolysis reaction degree in the constant power control mode area is gentle, and the electrolysis reaction degree in the constant voltage control mode area is intense. Electrolyte impurities are generated and accumulated during the electrolysis process. By increasing the brush speed, the accumulation of electrolyte impurities is reduced. In the constant current control mode area, due to the uneven thickness of impurities on the surface of the weld to be cleaned, the brush speed needs to be reduced to ensure the uniformity of the electrolysis reaction, thereby improving the electrolysis effect.

[0061] Furthermore, the method of the present invention adjusts the contact area of ​​the brush on the weld to be cleaned. Since the brush is still moving during the switching adaptive control mode, the cleaning of positions between different areas is incomplete. By increasing the contact area, the electrolysis uniformity and the electrolysis effect are improved.

[0062] Furthermore, the method of the present invention adjusts the electrolyte flow rate, and due to the increase in contact area, the temperature near the center of gravity in the connection area between the brush and the weld increases, which in turn affects the physical properties of the weld. By increasing the electrolyte flow rate to cool the connection position and prevent the electrolyte from overheating, the electrolysis stability and electrolysis efficiency are increased.

[0063] Furthermore, the method of the present invention avoids electrolyte instability and brush damage caused by excessive voltage fluctuations by setting the operating frequency of the switching mode power supply and the output ripple peak-to-peak value of the output voltage, thereby improving the stability and safety of the cleaning process. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is an overall flow chart of the weld cleaning method according to an embodiment of the present invention;

[0065] Figure 2 A schematic structural diagram of a weld cleaning device of a weld cleaning method according to an embodiment of the present invention;

[0066] Figure 3 A voltage-current schematic diagram of a control mode of a weld cleaning method according to an embodiment of the present invention;

[0067] Figure 4 A flow chart of adjusting the brush speed in the corresponding cleaning area of ​​the weld cleaning method according to an embodiment of the present invention;

[0068] Description of the accompanying figures: 1-handle, 2-electric telescopic rod, 3-electrolyte pump, 4-electrolyte container bottle, 5-weld to be cleaned, 6-electric brush, 7-welding part, 8-electric rotating table, 9-electrolyte delivery pipe DETAILED DESCRIPTION

[0069] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0070] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0071] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0072] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0073] See also Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, they are respectively an overall flow chart of the weld cleaning method according to an embodiment of the present invention, a schematic diagram of the weld cleaning device structure, a voltage-current schematic diagram, and a flow chart of adjusting the brush speed in the corresponding cleaning area. A weld cleaning method according to an embodiment of the present invention comprises:

[0074] Step S1, immersing the brushes on the weld cleaning device into the electrolyte in sequence and placing them on the weld to be cleaned;

[0075] Step S2, determining whether the switch mode power supply is switched from a constant power control mode to a control mode for a weld cleaning device according to the contact resistance of the brush, wherein the control mode further includes a constant current control mode and a constant voltage control mode;

[0076] Step S3, determining the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode according to the thickness of impurities on the weld to be cleaned, and pre-cleaning the weld to be cleaned;

[0077] Step S4, marking the weld areas affected by each control mode in the pre-cleaning process as corresponding cleaning areas;

[0078] Step S5, determining whether to adjust the brush speed of the brush in the corresponding cleaning area based on the fluctuation amplitude of the output voltage or output current of the weld cleaning equipment in the corresponding cleaning area,

[0079] Or, adjusting the contact area of ​​the brush at the moment of the jump according to the resistance when the control mode is triggered, and determining the propulsion rate of the electrolyte according to the temperature change in the contact area after the adjustment;

[0080] Step S6, starting the brush of the weld cleaning device to actually clean the weld to be cleaned according to the brush rotation speed / according to the contact area and the electrolyte flow rate;

[0081] Step S7, detecting the flatness of the weld surface to determine whether to repeat steps S5 to S7 until the flatness of the weld surface meets the requirements.

[0082] Specifically, the switch mode power supply of the weld cleaning device is a high-frequency power conversion device. The switch mode power supply is used to convert a voltage level into the voltage or current required for electrolysis through different forms of structures. The control mode conversion method of the switch mode power supply is an existing technology well known to those skilled in the art, so it will not be described in detail here.

[0083] Specifically, the switch mode power supply in the weld cleaning equipment also acts as the main inverter to limit the output voltage and output current within the range of + / -1.5% with an efficiency of >83%.

[0084] Specifically, the impurities on the weld 5 to be cleaned include iron oxides, aluminum oxides and nickel oxides.

[0085] Specifically, a handle 1 is provided on the weld cleaning device, an electric telescopic rod 2 is connected between the handle 1 and the brush 6, and an electric rotating platform 8 is connected between the electric telescopic rod 2 and the brush 6.

[0086] Specifically, the contact area is adjusted by adjusting the extrusion force between the brush 6 on the weld cleaning device and the weld 5 to be cleaned through the extension and retraction of the electric telescopic rod.

[0087] In implementation, the method of the present invention effectively reduces the ripple of the output voltage by using a high-frequency switching mode power supply, thereby improving the stability of the electrolyte. By adjusting the adaptive control mode, the output voltage and output current are adjusted separately. Due to the dynamic change of the contact resistance during the electrolysis process, the output current is too high when the resistance is reduced, which causes the electrolyte to overheat and burn, or the output voltage is insufficient to electrolyze the impurities due to the increase in resistance, resulting in incomplete electrolysis. By adjusting the control mode, the power is kept constant to increase the electrolysis stability. By keeping the output current constant, the current density in the brush is kept constant to increase the uniformity of the electrolysis of impurities. By keeping the output voltage constant, a current up to the maximum current is established according to the basic resistance, thereby achieving an improvement in the electrolysis efficiency. Since the brush is in contact with the impurities, the current density in the brush is kept constant to increase the uniformity of the electrolysis of impurities. During the electrolysis process, the intense electrolysis causes the electrolysis reaction temperature to increase, and the wetting degree on the brush decreases too quickly. The lower the wetting degree of the brush, the greater the resistance in the output circuit of the electrolysis device, which in turn increases the current, resulting in errors in the contact resistance of the switching adaptation control mode, and then causing damage to the weldment due to excessive current. By adjusting the delay time, the electrolysis accuracy is increased; by adjusting the brush speed and contact area of ​​the brush according to the electrolysis performance of different control modes, the cleaning effect is reduced in places with uneven contact resistance due to the constant current density of the brush under constant current control, or the impurities in the constant voltage control area require a large current, resulting in intense electrochemical reactions and impurities accumulation in the electrolyte. By adjusting the brush speed and contact area, the cleaning efficiency is improved and the cleaning stability and uniformity are improved.

[0088] Specifically, the start condition of the constant power control mode is that the contact resistance is within a preset resistance threshold.

[0089] The output power of the switch mode power supply in the weld cleaning device is proportional to the contact resistance, and the contact resistance is the ratio of the output voltage to the output current.

[0090] Specifically, the start-up condition of the constant voltage control mode is that the output voltage of the switch mode power supply is greater than or equal to a preset voltage, and the output current is less than a preset current.

[0091] Specifically, the start-up condition of the constant current control mode is that the output current of the switch mode power supply is greater than or equal to the preset current, and the output voltage is less than the preset voltage.

[0092] Specifically, the contact resistance depends on the material of the weld, the chemical reaction, and the conductivity of the electrolyte.

[0093] Specifically, the preset voltage is 36V, and the preset current is 95% of the rated current.

[0094] In implementation, the method of the present invention sets a preset resistance threshold, a preset voltage, and a preset current so that the adaptive control mode of the switch mode power supply changes with the required reaction conditions during the electrolysis process, thereby ensuring that in different electrolysis stages, the contact resistance changes between the brush 6 and the weld can be responded to and adapted in a timely manner. When the contact resistance is low, the method automatically switches to a constant power control mode to prevent the electrolyte from overheating due to excessive current. As the electrolysis process proceeds or the impurity composition or contact resistance changes, the contact resistance gradually increases, and then the method switches to a constant current control mode to keep the current density of the brush 6 constant, thereby improving the stability of the electrolysis. When the required current is too large, the method switches to a constant voltage control mode to fully electrolyze the impurities, thereby improving the electrolysis effect.

[0095] Specifically, the process of step S3 includes:

[0096] Collecting the maximum impurity thickness on the weld 5 to be cleaned;

[0097] When the maximum impurity thickness exceeds the preset thickness, it is determined that the wetting degree of the electrolyte does not meet the requirements, and the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode is increased.

[0098] The delay time is positively correlated with the maximum impurity thickness.

[0099] Specifically, the thickness of the impurities is detected by ultrasonic wave, and the thickness of the impurities is half of the product of the propagation speed of ultrasonic wave in the impurities and the reflection time.

[0100] Specifically, the delay time is adjusted by a time delay relay.

[0101] Specifically, the general value range of the preset thickness is [2.2mm, 2.4mm].

[0102] Preferably, the preset thickness is 2.3 mm.

[0103] During implementation, if the difference between the maximum impurity thickness and the preset thickness is within 0.1mm, the delay time is increased by 0.5s. If the difference between the maximum impurity thickness and the preset thickness exceeds 0.1mm, the delay time is increased by 0.4s for every 0.1mm exceeding the limit. For example, if the maximum impurity thickness is 2.6mm and the current delay time is 0s, the delay time is increased to 0s+0.5s+0.4s×2=1.3s.

[0104] Specifically, the process of step S5 includes:

[0105] Respectively obtain the cleaning area of ​​the weld seam 5 to be cleaned when the switch mode power supply is in the constant power control mode, the constant current control mode and the constant voltage control mode;

[0106] In the region of the constant power control mode, the brush speed remains unchanged;

[0107] In the region of the constant current control mode, if the fluctuation amplitude of the output voltage is greater than the second preset voltage fluctuation amplitude, it is determined that impurities in the electrolyte are dense, and the brush speed is reduced;

[0108] In the region of the constant voltage control mode, if the fluctuation amplitude of the output current is greater than the second preset current fluctuation amplitude, it is determined that the electrolytic reaction degree of the surface of the weld 5 to be cleaned does not meet the requirements, and the brush speed is increased.

[0109] The fluctuation amplitude of the output voltage is the absolute value of the difference between the maximum value and the minimum value of the output voltage in the region of the constant current control mode; the fluctuation amplitude of the output current is the absolute value of the difference between the maximum value and the minimum value of the output current in the region of the constant voltage control mode;

[0110] The brush speed in the constant current control mode is inversely proportional to the fluctuation amplitude of the output voltage; the brush speed in the constant voltage control mode is directly proportional to the fluctuation amplitude of the output current.

[0111] Specifically, the general value range of the preset second voltage fluctuation amplitude is [3.6V, 4.4V], and the general value range of the preset second current fluctuation amplitude is [1.2A, 1.5A].

[0112] Preferably, the preferred embodiment of the preset voltage fluctuation amplitude is 4V, and the preferred embodiment of the preset current fluctuation amplitude is 1.3A.

[0113] In implementation, when the difference between the output voltage fluctuation amplitude and the preset second voltage fluctuation amplitude is within 1V, the brush speed is reduced to 0.9 times the original value. If the difference between the output voltage fluctuation amplitude and the preset second voltage fluctuation amplitude exceeds 1V, the brush speed is reduced by 0.2r / s for every 1V exceeding it. For example, if the output voltage fluctuation amplitude is 6V and the current brush speed is 6r / s, the brush speed is reduced to 6r / s×0.9-0.2r / s=5.2r / s.

[0114] In implementation, when the difference between the output current fluctuation amplitude and the preset second current fluctuation amplitude is within 0.1A, the brush speed increases by 0.5r / s. If the difference between the output current fluctuation amplitude and the preset second current fluctuation amplitude exceeds 0.1A, the brush speed increases by 0.4r / s for every 0.1A exceeding it. For example, if the output current fluctuation amplitude is 1.5A and the current brush speed is 5r / s, the brush speed increases to 5r / s+0.5r / s+0.4r / s=5.9r / s.

[0115] Specifically, the brush speed of the brush 6 in the corresponding cleaning area is achieved by the electric rotating table in the weld cleaning device driving the brush 6 to move.

[0116] In implementation, the method of the present invention adjusts the brush speed according to different areas. Due to the uneven distribution of contact resistance in different areas, the same brush speed cannot better achieve the cleaning of the weld. The electrolysis reaction degree in the constant power control mode area is gentle, and the electrolysis reaction degree in the constant voltage control mode area is intense. Electrolyte impurities are generated and accumulated during the electrolysis process. By increasing the brush speed, the accumulation of electrolyte impurities is reduced. In the constant current control mode area, due to the uneven thickness of impurities on the surface of the weld 5 to be cleaned, the brush speed needs to be reduced to ensure the uniformity of the electrolysis reaction, thereby improving the electrolysis effect.

[0117] Specifically, the process of step S5 includes:

[0118] If the fluctuation amplitude of the output voltage is greater than or equal to the preset first voltage fluctuation amplitude and less than or equal to the preset second voltage fluctuation amplitude, or the fluctuation amplitude of the output current is greater than or equal to the preset first current fluctuation amplitude and less than or equal to the preset second current fluctuation amplitude, it is preliminarily determined that the impurity treatment uniformity does not meet the requirements, and the jump moment resistance when the adaptive control mode is triggered is obtained;

[0119] If the jump moment resistance is greater than or equal to the preset jump moment resistance, it is determined that the impurity treatment uniformity does not meet the requirements, and the contact area is increased.

[0120] The increase of the contact area is proportional to the resistance at the transition moment.

[0121] Specifically, the general value range of the preset first voltage fluctuation amplitude is [3V, 3.3V], and the general value range of the preset first current fluctuation amplitude is [0.8A, 1.2A].

[0122] Preferably, the preferred embodiment of the preset voltage fluctuation amplitude is 3.2V, and the preferred embodiment of the preset current fluctuation amplitude is 1A.

[0123] Specifically, the contact area between the brush 6 and the weld 5 to be cleaned is increased by increasing the pressure of the brush 6 .

[0124] Specifically, the general value range of the preset jump moment resistance is [75mΩ, 82mΩ].

[0125] Preferably, the preferred embodiment of the preset jump time resistance is 78 mΩ.

[0126] In practice, when the difference between the jump moment resistance and the preset jump moment resistance is within 1mΩ, the contact area increases to 1.05 times the original value. When the difference between the jump moment resistance and the preset jump moment resistance exceeds 1mΩ, the contact area increases by 1cm for every 1mΩ exceeding 1mΩ. 2 For example, the resistance at the time of the jump is 80mΩ, and the contact area between the current brush 6 and the weld 5 to be cleaned is 5cm 2 , the contact area increases to 5cm 2 ×1.05+1cm 2 =6.25cm 2 .

[0127] In implementation, the method of the present invention adjusts the contact area of ​​the brush on the weld to be cleaned. Since the brush is still moving during the switching adaptive control mode, incomplete cleaning of positions between different areas occurs. By increasing the contact area, improved electrolysis uniformity and improved electrolysis effect are achieved.

[0128] Specifically, the process of step S5 includes:

[0129] Obtaining a temperature change per unit time within the increased contact area of ​​the brush;

[0130] The advancement rate of the electrolyte increases with the increase of the temperature change.

[0131] The temperature change is the difference between the temperature at the end of the unit time and the temperature at the start of the unit time.

[0132] Specifically, the temperature within the increased contact area of ​​the brush is detected by a temperature sensor on the brush corresponding to the center position of the electric rotating table.

[0133] Specifically, the brush 6 is connected to an electrolyte container bottle 4, and an electrolyte pump 3 for adjusting the electrolyte propulsion speed is provided between the electrolyte container bottle 4 and the brush.

[0134] Specifically, an electrolyte delivery pipe 9 is provided between the brush 6 and the electrolyte pump 3, and an electrolyte delivery pipe 9 is provided between the electrolyte pump 3 and the electrolyte container bottle 4.

[0135] In practice, the method of the present invention adjusts the electrolyte flow rate, and due to the increase in contact area, the temperature near the center of gravity in the connection area between the brush and the weld increases, which in turn affects the physical properties of the weld. By increasing the electrolyte flow rate to cool the connection position and prevent the electrolyte from overheating, the electrolysis stability and efficiency are increased.

[0136] Specifically, in step S7, if the flatness is greater than or equal to the preset flatness, it is determined that the weld cleaning is not completed;

[0137] If the flatness is less than the preset flatness, it is determined that the weld cleaning is completed;

[0138] The flatness is the average thickness of impurities at each position on the weld 5 to be cleaned.

[0139] Specifically, the general value range of the preset flatness is (0mm, 0.05mm].

[0140] Preferably, the preset flatness is 0.02 mm.

[0141] Specifically, the operating frequency of the switch mode power supply is not less than 100 kHz, and the peak-to-peak value of the output ripple of the output voltage is not higher than 2000 mV.

[0142] In practice, the method of the present invention avoids electrolyte instability and brush 6 damage caused by excessive voltage fluctuations by setting the operating frequency of the switch mode power supply and the output ripple peak-to-peak value of the output voltage, thereby improving the stability and safety of the cleaning process.

[0143] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A weld cleaning method, characterized in that: include: Step S1, immersing the brushes on the weld cleaning device into the electrolyte in sequence and placing them on the weld to be cleaned; Step S2, determining whether the switch mode power supply is switched from a constant power control mode to a control mode for a weld cleaning device according to the contact resistance of the brush, wherein the control mode further includes a constant current control mode and a constant voltage control mode; Step S3, determining the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode according to the thickness of impurities on the weld to be cleaned, and pre-cleaning the weld to be cleaned; Step S4, marking the weld areas affected by each control mode in the pre-cleaning process as corresponding cleaning areas; Step S5, determining whether to adjust the brush speed of the brush in the corresponding cleaning area based on the fluctuation amplitude of the output voltage or output current of the weld cleaning equipment in the corresponding cleaning area, Or, adjusting the contact area of ​​the brush at the moment of the jump according to the resistance when the control mode is triggered, and determining the propulsion rate of the electrolyte according to the temperature change in the contact area after the adjustment; Step S6, starting the brush of the weld cleaning device to actually clean the weld to be cleaned according to the brush rotation speed / according to the contact area and the electrolyte flow rate; Step S7, detecting the flatness of the weld surface to determine whether to repeat steps S5 to S7 until the flatness of the weld surface meets the requirements.

2. The weld cleaning method according to claim 1, characterized in that: The starting condition of the constant power control mode is that the contact resistance is within a preset resistance threshold. The output power of the switch mode power supply in the weld cleaning device is proportional to the contact resistance, and the contact resistance is the ratio of the output voltage to the output current.

3. The weld cleaning method according to claim 2, characterized in that: The start-up condition of the constant voltage control mode is that the output voltage of the switch mode power supply is greater than or equal to a preset voltage, and the output current is less than a preset current.

4. The weld cleaning method according to claim 3, characterized in that: The start-up condition of the constant current control mode is that the output current of the switch mode power supply is greater than or equal to the preset current, and the output voltage is less than the preset voltage.

5. The weld cleaning method according to claim 4, characterized in that: The process of step S3 includes: Collecting the maximum impurity thickness on the weld to be cleaned; When the maximum impurity thickness exceeds the preset thickness, it is determined that the wetting degree of the electrolyte does not meet the requirements, and the delay time for switching from the constant power control mode or the constant current control mode to the constant voltage control mode is increased. The delay time is positively correlated with the maximum impurity thickness.

6. The weld cleaning method according to claim 5, characterized in that: The process of step S5 includes: Respectively obtaining a cleaning area of ​​the weld to be cleaned when the switch mode power supply is in the constant power control mode, the constant current control mode, and the constant voltage control mode; In the region of the constant power control mode, the brush speed remains unchanged; In the region of the constant current control mode, if the fluctuation amplitude of the output voltage is greater than the second preset voltage fluctuation amplitude, it is determined that impurities in the electrolyte are dense, and the brush speed is reduced; In the region of the constant voltage control mode, if the fluctuation amplitude of the output current is greater than the second preset current fluctuation amplitude, it is determined that the electrolytic reaction degree of the weld surface to be cleaned does not meet the requirements, and the brush speed is increased. The fluctuation amplitude of the output voltage is the absolute value of the difference between the maximum value and the minimum value of the output voltage in the region of the constant current control mode; the fluctuation amplitude of the output current is the absolute value of the difference between the maximum value and the minimum value of the output current in the region of the constant voltage control mode; The brush speed in the constant current control mode is inversely proportional to the fluctuation amplitude of the output voltage; the brush speed in the constant voltage control mode is directly proportional to the fluctuation amplitude of the output current.

7. The weld cleaning method according to claim 6, characterized in that: The process of step S5 includes: If the fluctuation amplitude of the output voltage is greater than or equal to the preset first voltage fluctuation amplitude and less than or equal to the preset second voltage fluctuation amplitude, or the fluctuation amplitude of the output current is greater than or equal to the preset first current fluctuation amplitude and less than or equal to the preset second current fluctuation amplitude, it is preliminarily determined that the impurity treatment uniformity does not meet the requirements, and the jump moment resistance when the adaptive control mode is triggered is obtained; If the jump moment resistance is greater than or equal to the preset jump moment resistance, it is determined that the impurity treatment uniformity does not meet the requirements, and the contact area is increased. The increase of the contact area is proportional to the resistance at the transition moment.

8. The weld cleaning method according to claim 7, characterized in that: The process of step S5 includes: Obtaining a temperature change per unit time within the increased contact area of ​​the brush; The advancement rate of the electrolyte increases with the increase of the temperature change. The temperature change is the difference between the temperature at the end of the unit time and the temperature at the start of the unit time.

9. The weld cleaning method according to claim 8, characterized in that: In the step S7, if the flatness is greater than or equal to the preset flatness, it is determined that the weld cleaning is not completed; If the flatness is less than the preset flatness, it is determined that the weld cleaning is completed; The flatness is the average impurity thickness at each position on the weld to be cleaned.

10. The weld cleaning method according to claim 1, characterized in that: The operating frequency of the switch mode power supply is not less than 100 kHz, and the peak-to-peak value of the output ripple of the output voltage is not higher than 2000 mV.

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